Rainbow Gate is the Prime-rarity card of the Starter Pack card set, most easily obtained by winning a Starter Pack B booster set (which contains three cards of at minimum Rare rarity), saving before you open it, and then reloading if Rainbow Gate is not obtained. In order to play Rainbow Gate in battle, you need to have a four-elemental deck: Nature, Fire, Water, and Earth. Rainbow Gate costs one of each of these elements to play, but it cannot be blocked by the opponent, and its effect is that you instantly win the match regardless of your opponent's current state.